Alcohol abuse during pregnancy is known to cause abnormalities in developing embryos and lead to fetal alcohol spectrum disorders (FASDs). However, the specific mechanisms by which alcohol mediates these injuries have yet to be determined. Stem cells during embryogenesis are under highly orchestrated molecular interplays among intrinsic stem cell factors that regulate stem cell potency and timely lineage specifications. In addition, there is evidence for the important roles of extrinsic factors within he stem cell microenvironment in ensuring proper fetal development. During embryogenesis there are significant intercellular communications between the mother and the developing embryo. Amniotic fluid serves as an important medium in the trafficking of molecular information between the mother and the fetus. It was also shown that amniotic fluid contains secreted exosomes with extracellular RNA (ExRNA) from both maternal and developing fetal tissues. Furthermore, alcohol was shown to significantly affect exosomal protein and RNA content in adult tissues. Thus, maternal alcohol consumption can significantly affect the microenvironment surrounding the developing embryo, including the biogenesis and the content of exosomal ExRNA. This exploratory application proposes to define the effect of maternal alcohol consumption during pregnancy on the biogenesis of amniotic ExRNA in the animal model of fetal alcohol exposure. Our central hypotheses are: (1) Maternal alcohol consumption alters the biogenesis of amniotic exosomes and ExRNA and (2) Maternal alcohol use alters the bio-function of amniotic exosomal ExRNA in fetal stem cell development. Two related Specific Aims are proposed to address these hypotheses: (SA1) To characterize the effect of alcohol on the biogenesis of amniotic exosomal ExRNA, and (SA2) To assess the effect of amniotic exosomal ExRNA in stem cell development. Defining the effect of maternal alcohol consumption on amniotic ExRNA content may be used to develop clinical tools to monitor the effects of alcohol on the pregnancy progress and fetal development. More importantly the identification of ExRNA species associated with FASDs will be beneficial towards development of biomarkers for early detection and interventions to prevent or mitigate EtOH's teratogenic effects.